Suction system for tensioning weft



1967 J. BIRMANS ETAL SUCTION SYSTEM FOR TENSIONING WEFT Filed Sept. 11, 1964 INVENTORS JOSEF BIRMANS AU UST WIRZ- I afi/h M/ ATTORNEY United States Patent 3,299,912 SUCTION SYTEM FOR TENSIONING WEFT Josef Birmans and August Wirz, Arbon, Thurgau, Switzerland, assignors to Adolph Saurer Ltd., Arbon, Thurgau, Switzerland Filed Sept. 11, 1964, Ser. No. 395,703 Claims priority, application Switzerland, Sept. 12, 1963, 11,322/ 63 3 Claims. (Cl. 139-194) This invention relates to looms and more particularly to looms of the kind wherein the weft is drawn off a stationary storage spool and inserted in the shed by weft inserting members not including any bobbins. More especially, the invention relates to suction devices for use in looms of the aforenoted type and designed to maintain the weft tensioned even after the ends of the weft have been released by the weft inserting member, until the reed has completed its stroke.

In the prior art, a device has been proposed which for the purpose of securing the weft ends by suction, is provide-d with small suction tubes arranged for displacement on the lay; these suction tubes enter the shed when the shuttle approaches, attract the weft ends as they slide ofl the shuttle, and while detaining the weft, leave the shed following the departure of the shuttle.

Another prior art device aimed at attracting the weft ends by suction and conveying the weft ends thus secured to a holding mechanism which during the stroke of the lay, held the weft in tensioned condition by firmly clamping the ends of the weft.

These prior art devices have in common that their designs are excessively complicated.

It is a primary object of the invention to provide an improved suction system for maintaining the weft tensioned until the end of the stroke of the reed, which is distinguished by greatly enhanced simplicity of construction.

It is another object of the present invention to provide a weft securing suction system for looms which favorably distinguishes over the prior art by greater simplicity of operation, reduced risk of failure, and materially reduced production costs.

Other objects, and the manner in which the same are attained, will become apparent as this specification proceeds.

In pursuit of the above-noted objectives, the invention contemplates suction nozzles arranged on the lay and on the spreader, respectively, the nozzle on the lay being adapted to surrender the ends of the weft introduced into the shed to the nozzle on the spreader in the course of the forward stroke of the lay.

It is this combination of a first nozzle mounted on the lay and a second nozzle adjacent the temple on one and the same loom which guarantees that the ends of the weft will be securely held while the lay moves from the rear dead center to closure of the shed and then from the closure of the shed to the impact of the reed to thereby prevent the thread ends from being drawn into the textile during the insertion of subsequent weft threads.

The suction nozzles are valve controlled in such a manner that the nozzle on the lay is activated, i.e. maintained under suction, while the lay moves from rear dead center to closure of the shed, and the nozzle on the spreader is activated from closure of the shed to impact of the reed. A common control valve is provided for the suction nozzle on the lay and the nozzle on the spreader. The nozzles may be provided as regular suction nozzles, or else as injectors; in the latter case they are controlled by a common control valve controlling the flow of compressed air.

In the drawing accompanying this application and forming part thereof, two embodiments of the invention are illustrated diagrammatically by way of example, rather than with any limitative intent.

In the drawing:

FIG. 1 is a diagrammatic representation, in perspective, of the essential parts only of a loom provided with a suction system according to the invention, and

FIG. 2 is a similar showing of part of a loom equipped with a modified, injector type pneumatic system according to the invention.

Referring to the drawing wherein like elements are denoted by identical reference numerals, and first to FIG. 1, this shows a lay 1, mounted for back and forth displacement on a sword 2. The reed 3 is mounted on the lay 1. The spreader 4 including shears is disposed on both sides of the fabric 5. The suction nozzle 6 is mounted on the lay 1, its suction port 10 being disposed in proximity to the outermost lower shed threads 11. The suction nozzle 7 terminating in suction port 12 is mounted on the spreader 4, in any suitable manner not requiring illustration. Ends 13 and 14 of the nozzles 6 and 7 remote from the suction ports 10 and 12, respectively, are connected with a control valve 9. Via rod 15 the control valve 9 is imparted a reciprocating rotary motion by the picking shaft 16 which revolves at half the number of revolutions of the drive 17 for sword 2.

Control valve 9 is arranged to connect the nozzle 6 with the conduit 8 leading to the source of vacuum (not shown) when the lay 1 is in rear dead center, and to connect the nozzle 7 with'conduit 8 when the lay 1 is in front dead center.

In order to more clearly illustrate the essence of the invention, the weft inserting member is omitted in the drawing which shows, however, weft 18 already introduced into the shed, as well as its left end portion 19.

The operation of the suction system according to FIG. 1 is as follows:

In the position illustrated in the drawing, the weft inserting member has emerged from the shed on the left, and lay 1 has passed its rear dead center. The control valve 9 connects nozzle 6 with conduit 8, with the result that the weft end 19 is drawn in by suction port 10. Nozzle 6 on lay 1 remains under vacuum while lay 1 proceeds from rear dead center to closure of the shed. When the shed closes and very shortly before the impact of the reed, valve 9 changes its position so that in place of nozzle 6, nozzle 7 is connected with the vacuum. When this change-over takes place, suction port 10 has reached a position underneath suction port 12, and the weft end 19 so far held by suction from port 10, is now surrendered to the control of suction port 12. The weft end 19 remains in the nozzle aperture 12, and therefore maintains the weft 18 in tensioned condition, until end 19 is separated from the selvedge by the shears arranged on spreader 4, the separated weft end 19 being then carried away through the nozzle 7 and the suction conduit 8.

Referring now to the embodiment of the invention illustrated in FIG. 2, this includes nozzles 20 and 21 associated with injectors 22 and 23, respectively. Compressed air lines 24 and 25 leading to injectors 22 and 23, respectively, are connected with a pressure valve 26.

While being similar in most respects to the embodiment of FIG. 1, the device shown in FIG. 2 involves the important advantage that the injectors 22 and 23 can be disposed in immediate proximity to suction ports 27 and 28, respectively, whereby a materially increased suction effect is secured. Another advantage of the embodiment of the invention of FIG. 2 resides in that the cut ends of the weft are not carried away through the suction system including the control valve 26, as in FIG. 1, but are conveyed through conduit 30 directly to a waste collector 31 without passing through the valve.

We wish it to be understood that we do not desire to 3, be limited to the exact details of construction, design and operation shown and described, as modifications within the scope of the appended claims and involving no departure from the spirit of the invention nor sacrifice of the advantages thereof, may occur to workers in the field.

We claim:

1. In a loom including a drive for imparting reciprocating rotary motion by means of shafts connected thereto, a shed, a lay arranged for back and forth displacement from rear dead center to closure of said shed, a reed associated with said lay, a spreader and a weft inserting member in which there is provided no bobbin for inserting the weft for storage into the shed, a vacuum tensioning device comprising in combination: a first suction nozzle which is mounted on the lay and which is operatively connected to a vacuum source so that when the lay moves from rear dead center to closure of said shed the weft is tensioned in this first movement; a second suction nozzle which is mounted on said spreader and which is operatively connected to the vacuum source for effecting the References Cited by the Examiner UNITED sTATEs PATENTS 1,921,396 8/1933 Pool 139 127 1,963,098 6/1934 PO01 139127 2,089,620 8/1937 Rossmann 139 194 2,762,399 9/1956 Moseley et al 139 1703 2,842,164 7/1958 Head 139 -170.3 2,906,296 9/1959 Ancetetal. 139 291 3,050,088 8/1962 Schaffer 139194X 3,147,778 9/1964 Reyes 139 303 3,186,444 6/1965 Schaffer 139 194 X FOREIGN PATENTS 1,237,767 6/1960 France. 1,348,802 12/1963 France.

MERVIN STEIN, Primary Examiner.

DONALD W. PARKER, J. KEECHI,

Assistant Examiner's. 

1. IN A LOOM INCLUDING A DRIVE FOR IMPARTING RECIPROCATING ROTARY MOTION BY MEANS OF SHAFTS CONNECTED THERETO, A SHED, A LAY ARRANGED FOR BACK AND FORTH DISPLACEMENT FROM REAR DEAD CENTER TO CLOSURE OF SAID SHED, A REED ASSOCIATED WITH SAID LAY, A SPREADER AND A WEFT INSERTING MEMBER IN WHICH THERE IS PROVIDED NO BOBBIN FOR INSERTING THE WEFT FOR STORAGE INTO THE SHED, A VACUUM TENSIONING DEVICE COMPRISING IN COMBINATION: A FIRST SUCTION NOZZLE WHICH IS MOUNTED ON THE LAY AND WHICH IS OPERATIVELY CONNECTED TO A VACUUM SOURCE SO THAT WHEN THE LAY MOVES FROM REAR DEAD CENTER TO CLOSURE OF SAID SHED THE WEFT IS TENSIONED IN THIS FIRST MOVEMENT; A SECOND SUCTION NOZZLE WHICH IS MOUNTED ON SAID SPREADER AND WHICH IS OPERATIVELY CONNECTED TO THE VACUUM SOURCE FOR EFFECTING THE CLOSURE OF SAID SHED TO THE IMPACT OF SAID REED; A COMMON SOURCE OF VACUUM TO WHICH SAID FIRST AND SECOND SUCTION NOZZLES ARE CONNECTED, SAID VACUUM SOURCE INCLUDING COMMON VALVE MEANS FOR CONNECTING SAID VACUUM SOURCE TO SAID FIRST AND SECOND SUCTION NOZZLES; SAID COMMON VALVE MEANS BEING OPERATIVELY CONTROLLED BY SAID RECIPROCATING ROTARY DRIVE, WHEREBY THE WEFT ENDS ARE HELD BY SAID FIRST SUCTION NOZZLE TO MAINTAIN THE WEFT IN TENSIONED CONDITION AND ARE SURRENDERED TO SAID SECOND SUCTION NOZZLE. 